Major parts of the EasternProvince of Saudi Arabia are covered with the
windblown dune sand which is characterized as poorly graded soil with high
permeability. Also, marl which is available in abundance in this region has a
poor strength. It is usually required to use these materials as subgrade layers or as a backfill in base and subbase layers of roads and highways. With the low strength
characteristics of these materials and the high water table in the region, some
sort of stabilization is needed to improve the characteristics of these
materials. In this research, slow setting emulsified asphalt and medium curing
cutback asphalt were used to stabilize both mart and dune sand. 2% and 4% lime
and Portland cement were added to the stabilized soils to accelerate curing
process and to reduce stability loss due to water damage. It was found that the
stabilizing aggregates have both improved shear strength and resistance of the
analyzed soils to water damage. It was also recalled that an additive like
Portland cement was more effective than lime.